Diet homogenisation is shrinking biodiversity: Why India must revive local vegetable varieties

Vegetable biodiversity is the variety of vegetable species and forms grown, eaten or preserved, including local landraces and wild relatives. It matters because vegetables support food security, nutrition and climate resilience. They also include many plant parts, such as sweet-potato roots and leaves.

Diet homogenisation means people increasingly eat the same limited group of vegetables. Market demand often favours uniform crops that are easy to produce and sell. The article reports that markets are dominated by hybrids, while many local and wild vegetables are missing from standard references. This narrows the range of crops farmers grow and consumers encounter.

The loss is difficult to notice because common vegetables remain abundant. Yet researchers warn that land-use change, market homogenisation and species extinction have already reduced vegetable biodiversity significantly. Conserving and using more varieties can keep forgotten foods in cultivation and make food systems better prepared for changing conditions.

The researchers’ Global Vegetable Species Dataset documents 1,482 vegetable species. The article notes that the true number is probably higher because many local and wild vegetables are absent from standard references. Documentation therefore shows only part of the world’s vegetable diversity.

Conservation collections are substantial but incomplete. The World Vegetable Center’s WorldVeg Genebank holds more than 65,000 accessions, or genetic samples, covering more than 330 vegetable species. India’s National Bureau of Plant Genetic Resources holds more than 30,700 vegetable accessions, including okra, brinjal, tomato and onion.

The scale of risk remains serious. About 24% of the wild relatives of 79 major vegetable species are threatened with extinction. Several landraces also remain unknown, making losses hard to measure. The priority is not only to store seeds, but to bring diversity back into use.

Local vegetables become rare when farming and markets reward a narrow range of uniform crops. The article links vegetable biodiversity loss to land-use change, market homogenisation and the extinction of native and wild species. Once a variety is no longer widely grown, its seeds, knowledge and consumer demand can also become harder to maintain.

Clove bean, once common in south Indian kitchens, is now rarely seen in markets. Prabhakar Rao conserves it at his Bengaluru farm. He also recalls that Yerengere white long eggplant was once the brinjal used for vangi bath, but markets now contain many hybrids and fewer traditional choices.

The decline remains largely unnoticed because common vegetables are still available in abundance. This creates the impression that food diversity is safe. Rao’s seed-saving work shows that cultivation outside mainstream markets can keep forgotten varieties alive, while wider use could help restore them to diets.

Vegetable diversity supports food security, nutrition and climate resilience. Different species and varieties can provide different foods, edible plant parts and useful traits. When fewer crops dominate, food systems have fewer options to draw on when conditions change or a crop performs poorly.

The article highlights sweet potato and taro as dual-purpose vegetables: their roots are eaten, and their leaves are also consumed. It also describes vegetables broadly, including tomatoes as fruits, sweet potatoes as roots, artichokes as flowers and green soybeans as seeds. This versatility expands how vegetables contribute to diets.

Homogenisation also hides losses. Consumers may still find familiar vegetables in abundance, while rare landraces and wild relatives disappear. The article identifies climate resilience as a crucial reason to conserve diversity. Using overlooked crops such as minor yams, pumpkin and sweet potato can help build more resilient food systems.

In standard crop terminology, heirloom seeds come from older varieties maintained across generations, often by farmers or gardeners. Landraces are locally developed populations shaped by regional conditions and farmer selection. They may be less uniform but can carry valuable local adaptation. The article discusses both as forms of diversity that may remain poorly known.

Wild relatives are related plant species or populations that have not been fully domesticated. They can contain traits useful for future breeding, yet the article warns that about 24% of wild relatives linked to 79 major vegetable species are at risk. Their loss can happen before their value is understood.

Hybrid varieties are produced by crossing selected parent lines, often to provide desired traits and consistent market performance. The article says today’s markets are dominated by hybrids. Hybrids are not inherently harmful, but relying mainly on them can reduce the cultivation and visibility of heirlooms, landraces and wild relatives.

Conservation can move beyond market-led uniformity by protecting seeds, documenting neglected varieties and supporting farmers who continue growing them. The article stresses that the goal is not simply to store diversity. It is also to ensure that diversity is used.

Hariyalee Seeds provides one example. Prabhakar Rao has saved hundreds of heirloom vegetable varieties at his Bengaluru farm, including clove bean and Yerengere white long eggplant. Genebanks provide another safeguard by storing accessions. The Opportunity Crops Knowledge Base documents 20 overlooked crops, including sweet potato, minor yams and pumpkin, as possible contributors to resilient food systems.

Bringing these crops into cultivation and diets can rebuild demand and knowledge. Local farms, public genebanks, researchers and consumers can therefore complement commercial markets. The article presents use as the next step after rescue: conserved seeds must remain available for farming, cooking and adaptation.

Genebanks protect vegetable diversity by storing accessions, or genetic samples, for future conservation and use. The WorldVeg Genebank holds more than 65,000 accessions from over 330 vegetable species. India’s National Bureau of Plant Genetic Resources stores more than 30,700 vegetable accessions, including okra, brinjal, tomato and onion.

Farmers and seed conservers protect diversity in fields and gardens. Prabhakar Rao, founder of Hariyalee Seeds, has saved hundreds of heirloom varieties from around the world. His Bengaluru farm keeps rare vegetables such as clove bean visible and potentially cultivable. This complements genebank storage by maintaining practical knowledge and living examples.

Researchers and organisations also identify what is missing and why it matters. The PNAS authors created a dataset of 1,482 vegetables, while Crop Trust established a knowledge base for 20 overlooked crops. The shared aim is to rescue diversity and ensure it is used in food systems.